A professor has noticed that even though attendance is not a

A professor has noticed that, even though attendance is not a component of the final grade for the class, students that attend regularly generally get better grades. In fact, 51% of those who come to class on a regular basis receive A\'s. Only 10% who do not attend regularly get A\'s. The long run attendance rate is 84%. Based on this class profile, suppose we are randomly selecting a single student from this class, and answer the questions below. Hint #1: pretend that there are 1000 students in the class and use the values given in the problem to construct the appropriate contingency table. Round cell frequencies to the nearest integer Hint #2: No joke, you really need to use hint #1. Hint #3: The first step to using hint #1 is to calculate the totals for those who attend regularly and do not attend regularly using the \'long run attendance rate\'.

P(receives A\'s) =

P(attends regularly | receives A\'s) =

Solution

A professor has noticed that, even though attendance is not a component of the final grade for the class, students that attend regularly generally get better grades. In fact, 51% of those who come to class on a regular basis receive A\'s. Only 10% who do not attend regularly get A\'s. The long run attendance rate is 84%. Based on this class profile, suppose we are randomly selecting a single student from this class, and answer the questions below. Hint #1: pretend that there are 1000 students in the class and use the values given in the problem to construct the appropriate contingency table. Round cell frequencies to the nearest integer Hint #2: No joke, you really need to use hint #1. Hint #3: The first step to using hint #1 is to calculate the totals for those who attend regularly and do not attend regularly using the \'long run attendance rate\'.

Regular

Irregular

Total

A

428

16

444

No A

412

144

556

Total

840

160

1000

P(receives A\'s) = 444/1000 =0.444

P(attends regularly | receives A\'s) = 428/444 =0.96396